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Fetal methemoglobinemia: A cause of nonimmune hydrops fetalis
&men
et al. Am J Obstet
REFERENCES
Spontaneous rupture of the spleen is a very rare situation in a pregnant patient. It is important to keep this possibility in mind when there is evidence of intraperitoneal bleeding, even after cesarean section. Awareness of the possibility and use of ultrasonographic examinations to demonstrate increasing fluid collection was helpful to take prompt action and save this patient.
Fetal methemoglobinemia: hydrops fetalis Selale U@r
Ankara,
&men,
MD,
Dilmen,
MD
Neslihan
Seqkin,
MD,
Nilgiin
July 1995 Gynecol
1. Denehy T, McCrath EW, Breen L. Splenic torsion and rupture in pregnancy. Obstet Gynecol Sun, 1988;43:12331. 2. Fletcher H, Frederick J, Barned H, Lizarraga V. Spontaneens rupture of the spleen in pregnancy with splenic conservation. West Indian Med J 1989;38:114-5.
A cause of nonimmune 0.
Turhan,
MD,
Giilqin
Dilmen,
MD,
and
Turkey
A case of nonimmune hydrops fetalis resulting from fetal methemoglobinemia is presented. A woman with a pregnancy at 17 weeks’ gestation was admitted after combustion gas intoxication. Although the mother totally recovered, the fetus showed signs of nonimmune hydrops fetalis at follow-up. Fetal methemoglobin levels were very high. (AM J OBSTET GYNECOL 1995;173:232-3.) Key
words:
Fetal methemoglobinemia,
intoxication,
nonimmune
Combustion toxicology is so complex that it leads to a number of risks depending on the substances inhaled. Although victims are primarily treated symptomatically, it is important to identify those situations when specific therapeutic managements are required.’ The problem is even more complex when the victim is pregnant. We report the fetal outcome of a pregnant woman intoxicated by a malfunctioning heater.
Case report An l&year-old pregnant woman was found intoxicated by a malfunctioning heater used for obtaining hot water. The heater used a commercially available gas, a mixture of butane and propane. She was unconscious when found and received respiratory resuscitation and normobaric oxygen at an emergency care center. Neither the levels of carbon monoxide nor carboxyhemoglobin were measured. She was admitted to our hospital approximately 48 hours after the intoxication because of her concern for her pregnancy. She was fully recovered. At the time she was in her first pregnancy of 17 weeks of gestation. An From the Turkish Health and Therapy Foundation Medical Center. Received for publication July 12, 1994; revised November 15, 1994; accepted November 18, 1994. Reprints not available from the authors. Copyright 0 1995 by Mosby-Year Book, Inc. 0002-9378/95 $3.00 + 0 6/l/62314
232
hydrops
fetalis
ultrasonographic examination was performed. The fetal measurements were found to be appropriate for the gestational age, no congenital malformation was detected, and fetal cardiac activity was normal. During the scanning there was no sign of fetal movement. A second scan was performed 2 weeks later. The fetal measurements were appropriate for the gestational age, and still there was no fetal movement. The fetal habitus was the same as in the previous scan. Fetal cardiac activity was normal. A scalp edema was detected. A third ultrasonographic examination was performed 1 week later. There were signs of hydrops fetalis. Doppler studies of the umbilical artery were within normal limits for the gestational age of 20 weeks (systolic/diastolic ratio 5.23, pulsatility index 1.98, resistance index 0.82). A cordocentesis was performed. The results of the laboratory tests are shown in Table I. When fetal anemia was detected, intrauterine blood transfusion was recommended; however, the parents did not accept. The fetal karyotype was 46,XY. At cordocentesis the measurements of carboxyhemoglobin and methemoglobin levels were not available; we stored the blood sample. One week later the fetal signs of hydrops fetalis were increased. The family requested termination of the pregnancy. At 21 weeks of gestation, 4 weeks after the
Volume 173, Number Am J Obstet Gynecol
Table
I. Laboratory
1
Cizmen
results Maternal
Blood group Indirect Coombs’ test Direct Coombs’ test Hemoglobin (gmidl) Hematocrit (%) Carbon monoxide (mg/L) Carboxyhemoglobin Methemoglobin Glutathione reductase deficiency *Lower tLeve1
than could
et al. 233
levels of intoxication. not be measured quantitatively
B, Rh negative Negative 14.8 46.6 Not measured Not measured Not found Not found
because
of inadequate
intoxication, the pregnancy was terminated by intraamniotic ethacridine lactate (Rivanol, Ega? AS., Ankara, Turkey) (with a concentration of 0.3%) instillation. The postmortem findings were consistent with the ultrasonographic examination. A postmortem blood sample was drawn. The laboratory results are listed in Table I. Comment W7e present a case of combustion gas intoxication affecting the fetus. At admission the diagnosis was carbon monoxide intoxication. Although the physical examination of the mother was completely normal, the fetal consequences were severe. Among the cases of carbon monoxide poisoning published in the English language medical literature, there are cases of stillbirth, fetal brain damage, and neurologic disorders.’ However, there is no report of nonimmune hydrops fetalis. Therefore we carried out some tests to identify whether this finding was related to intoxication or was coincidental. After these examinations, the hydrops was considered to be a result of fetal anemia. Surprisingly, both fetal blood samples, the first one 3 weeks after the intoxication and the second one postmortally, revealed high levels of methemoglobin. The carbon monoxide levels were very low and carboxyhemoglobin was not detected. The mother was screened for methemoglobinemia and glutathione reductase deficiency. Neither was found. Kulling’ has reported that in victims of combustion gas intoxication methemoglobinemia may be induced by exposure to nitrogen oxides. Nitrogen oxides might be released from nitrocellulose, polyamides, and other nitrogen-containing materials. The immediate symptoms of nitrogen oxide intoxication may be mild or even absent, and acquired methemoglobinemia is usually mild and poses no major clinical problems.‘, ’ This
volume
Fetal samfile I (cordocentesis)
Fetal sample 2 (post mortem)
B, Rh positive Negative 4.7 14.2 0.04* Not detected Very high?
B, Rh positive Negative 6.8 18.9 0.07* Not detected Very high?
of samples,
could be why the mother had not shown any signs of methemoglobinemia. We believe that the anemia detected in the fetus was the result of methemoglobinemia. The cause of methemoglobinemia might be the nitrogen oxides released during the intoxication. The level of cytochrome b, reductase in the newborn is low (50%) and probably accounts for the susceptibility of newborns to oxidants and acquired methemoglobinemia.3 This must be the case in the fetus as well. Methemoglobinemia can be treated with hemoglobin-reducing agents such as methylene or toluidine blue or ascorbic acid.‘. 3 We are not sure whether these substances would have helped to reduce the fetal methemoglobin levels in our case. We believe that experimental work might be necessary to reveal whether combustion gases and nitrogen oxides cause fetal methemoglobinemia and what would be the route of treatment. This is an interesting case of nonimmune hydrops fetalis caused by methemoglobinemia, and it alerts clinicians that in victims of combustion gas intoxication, besides symptomatic treatment, sometimes special therapeutic measures might be of importance. In a pregnant victim the case is even more complex. We thank Prof. P. Levillain and Dr. F. Buneaux from Laboratoire Biochimie Toxicologic, Hopital Fernand Vidal, Paris, for their help in measuring the fetal carbon monoxide, carboxyhemoglobin, and methemoglobin levels.
REFERENCES
1. Kulling P. Hospital treatment of victims exposed to combustion products. Toxic01 Lett 1992;65:283-8. 2. Koren C, Sharav T, Pastuszak A, et al. A multicenter prospective study of fetal outcome following accidental carbon monoxide poisoning in pregnancy. Reprod Toxicol 1991;5:397-403. 3. Mansouri A, Lurie AA. Concise review: methemoglobinemia. Am J Hematol 1993;42:7-12.
et al. Am J Obstet
REFERENCES
Spontaneous rupture of the spleen is a very rare situation in a pregnant patient. It is important to keep this possibility in mind when there is evidence of intraperitoneal bleeding, even after cesarean section. Awareness of the possibility and use of ultrasonographic examinations to demonstrate increasing fluid collection was helpful to take prompt action and save this patient.
Fetal methemoglobinemia: hydrops fetalis Selale U@r
Ankara,
&men,
MD,
Dilmen,
MD
Neslihan
Seqkin,
MD,
Nilgiin
July 1995 Gynecol
1. Denehy T, McCrath EW, Breen L. Splenic torsion and rupture in pregnancy. Obstet Gynecol Sun, 1988;43:12331. 2. Fletcher H, Frederick J, Barned H, Lizarraga V. Spontaneens rupture of the spleen in pregnancy with splenic conservation. West Indian Med J 1989;38:114-5.
A cause of nonimmune 0.
Turhan,
MD,
Giilqin
Dilmen,
MD,
and
Turkey
A case of nonimmune hydrops fetalis resulting from fetal methemoglobinemia is presented. A woman with a pregnancy at 17 weeks’ gestation was admitted after combustion gas intoxication. Although the mother totally recovered, the fetus showed signs of nonimmune hydrops fetalis at follow-up. Fetal methemoglobin levels were very high. (AM J OBSTET GYNECOL 1995;173:232-3.) Key
words:
Fetal methemoglobinemia,
intoxication,
nonimmune
Combustion toxicology is so complex that it leads to a number of risks depending on the substances inhaled. Although victims are primarily treated symptomatically, it is important to identify those situations when specific therapeutic managements are required.’ The problem is even more complex when the victim is pregnant. We report the fetal outcome of a pregnant woman intoxicated by a malfunctioning heater.
Case report An l&year-old pregnant woman was found intoxicated by a malfunctioning heater used for obtaining hot water. The heater used a commercially available gas, a mixture of butane and propane. She was unconscious when found and received respiratory resuscitation and normobaric oxygen at an emergency care center. Neither the levels of carbon monoxide nor carboxyhemoglobin were measured. She was admitted to our hospital approximately 48 hours after the intoxication because of her concern for her pregnancy. She was fully recovered. At the time she was in her first pregnancy of 17 weeks of gestation. An From the Turkish Health and Therapy Foundation Medical Center. Received for publication July 12, 1994; revised November 15, 1994; accepted November 18, 1994. Reprints not available from the authors. Copyright 0 1995 by Mosby-Year Book, Inc. 0002-9378/95 $3.00 + 0 6/l/62314
232
hydrops
fetalis
ultrasonographic examination was performed. The fetal measurements were found to be appropriate for the gestational age, no congenital malformation was detected, and fetal cardiac activity was normal. During the scanning there was no sign of fetal movement. A second scan was performed 2 weeks later. The fetal measurements were appropriate for the gestational age, and still there was no fetal movement. The fetal habitus was the same as in the previous scan. Fetal cardiac activity was normal. A scalp edema was detected. A third ultrasonographic examination was performed 1 week later. There were signs of hydrops fetalis. Doppler studies of the umbilical artery were within normal limits for the gestational age of 20 weeks (systolic/diastolic ratio 5.23, pulsatility index 1.98, resistance index 0.82). A cordocentesis was performed. The results of the laboratory tests are shown in Table I. When fetal anemia was detected, intrauterine blood transfusion was recommended; however, the parents did not accept. The fetal karyotype was 46,XY. At cordocentesis the measurements of carboxyhemoglobin and methemoglobin levels were not available; we stored the blood sample. One week later the fetal signs of hydrops fetalis were increased. The family requested termination of the pregnancy. At 21 weeks of gestation, 4 weeks after the
Volume 173, Number Am J Obstet Gynecol
Table
I. Laboratory
1
Cizmen
results Maternal
Blood group Indirect Coombs’ test Direct Coombs’ test Hemoglobin (gmidl) Hematocrit (%) Carbon monoxide (mg/L) Carboxyhemoglobin Methemoglobin Glutathione reductase deficiency *Lower tLeve1
than could
et al. 233
levels of intoxication. not be measured quantitatively
B, Rh negative Negative 14.8 46.6 Not measured Not measured Not found Not found
because
of inadequate
intoxication, the pregnancy was terminated by intraamniotic ethacridine lactate (Rivanol, Ega? AS., Ankara, Turkey) (with a concentration of 0.3%) instillation. The postmortem findings were consistent with the ultrasonographic examination. A postmortem blood sample was drawn. The laboratory results are listed in Table I. Comment W7e present a case of combustion gas intoxication affecting the fetus. At admission the diagnosis was carbon monoxide intoxication. Although the physical examination of the mother was completely normal, the fetal consequences were severe. Among the cases of carbon monoxide poisoning published in the English language medical literature, there are cases of stillbirth, fetal brain damage, and neurologic disorders.’ However, there is no report of nonimmune hydrops fetalis. Therefore we carried out some tests to identify whether this finding was related to intoxication or was coincidental. After these examinations, the hydrops was considered to be a result of fetal anemia. Surprisingly, both fetal blood samples, the first one 3 weeks after the intoxication and the second one postmortally, revealed high levels of methemoglobin. The carbon monoxide levels were very low and carboxyhemoglobin was not detected. The mother was screened for methemoglobinemia and glutathione reductase deficiency. Neither was found. Kulling’ has reported that in victims of combustion gas intoxication methemoglobinemia may be induced by exposure to nitrogen oxides. Nitrogen oxides might be released from nitrocellulose, polyamides, and other nitrogen-containing materials. The immediate symptoms of nitrogen oxide intoxication may be mild or even absent, and acquired methemoglobinemia is usually mild and poses no major clinical problems.‘, ’ This
volume
Fetal samfile I (cordocentesis)
Fetal sample 2 (post mortem)
B, Rh positive Negative 4.7 14.2 0.04* Not detected Very high?
B, Rh positive Negative 6.8 18.9 0.07* Not detected Very high?
of samples,
could be why the mother had not shown any signs of methemoglobinemia. We believe that the anemia detected in the fetus was the result of methemoglobinemia. The cause of methemoglobinemia might be the nitrogen oxides released during the intoxication. The level of cytochrome b, reductase in the newborn is low (50%) and probably accounts for the susceptibility of newborns to oxidants and acquired methemoglobinemia.3 This must be the case in the fetus as well. Methemoglobinemia can be treated with hemoglobin-reducing agents such as methylene or toluidine blue or ascorbic acid.‘. 3 We are not sure whether these substances would have helped to reduce the fetal methemoglobin levels in our case. We believe that experimental work might be necessary to reveal whether combustion gases and nitrogen oxides cause fetal methemoglobinemia and what would be the route of treatment. This is an interesting case of nonimmune hydrops fetalis caused by methemoglobinemia, and it alerts clinicians that in victims of combustion gas intoxication, besides symptomatic treatment, sometimes special therapeutic measures might be of importance. In a pregnant victim the case is even more complex. We thank Prof. P. Levillain and Dr. F. Buneaux from Laboratoire Biochimie Toxicologic, Hopital Fernand Vidal, Paris, for their help in measuring the fetal carbon monoxide, carboxyhemoglobin, and methemoglobin levels.
REFERENCES
1. Kulling P. Hospital treatment of victims exposed to combustion products. Toxic01 Lett 1992;65:283-8. 2. Koren C, Sharav T, Pastuszak A, et al. A multicenter prospective study of fetal outcome following accidental carbon monoxide poisoning in pregnancy. Reprod Toxicol 1991;5:397-403. 3. Mansouri A, Lurie AA. Concise review: methemoglobinemia. Am J Hematol 1993;42:7-12.